Former Sen. Rick Santorum of Pennsylvania officially began his 2012 presidential race Monday, carrying with him a strong record as a social conservative and a message of fiscal restraint that he hopes to ride into the White House.

Mr. Santorum, in announcing his bid, criticized President Obama as having put the country on a path to moral and fiscal ruin and for passing a health care overhaul that the Pennsylvanian said runs contrary to the founding American principles that encouraged his grandfather to emigrate here from Italy.

“I’m ready to lead,” Mr. Santorum told the hundreds gathered for the announcement. “I’m ready to do what has to be done for the next generation, with the courage to fight for freedom, with the courage to fight for America.”

“That’s why I’m announcing today that I’m running for president of the United States of America.”

The Republican, though, has serious hurdles to overcome to become the party’s nominee. The barriers range from his crushing double-digit loss in his 2006 re-election bid to his low name recognition in early primary states and the fact that he’s known more as a crusader on abortion and traditional marriage than on the fiscal issues that are first and foremost on voters’ minds — particularly tea partyers who played a big role in the Republican takeover of the U.S. House.

“I don’t know if he brings anything special to tea party voters in terms of fiscal matters, but his overall conservative record should at least deem a look from GOP primary voters in Iowa and New Hampshire,” said Christopher P. Borick, a political science professor at Muhlenberg College.

Chris Chocola, president of the Club for Growth, an influential anti-tax group, said Mr. Santorum has a “strong record on taxes, and his leadership on welfare reform and Social Security was exemplary.”

“But his record also contains several very weak spots, including his active support of wasteful spending earmarks, his penchant for trade protectionism, and his willingness to support more government spending,” Mr. Chocola said.

Gary L. Bauer, president of American Values, a socially conservative group, said that Mr. Santorum has a shot.

“In a field where people are still looking for who the conservative favorite will be, he’s got a decent chance to emerge,” Mr. Bauer said, arguing that Mr. Santorum’s economic and foreign-policy credentials are strong. “I think he could end up surprising people.”

On Monday, flanked by his wife and seven children, Mr. Santorum repeated the early message of his campaign that the rights of people come from God, not from government.

“The principal purpose of America was to make sure each and every one of us was free,” he said. “Ladies and gentlemen, that is at stake now more than it has ever been in the modern time.”

That message and Mr. Santorum’s record appears to dovetail well with evangelical and family-values voters in Iowa and South Carolina. But the jury is still out as to whether he can make inroads with the more libertarian-leaning voters in New Hampshire, home to the first-in-the-nation primary.

“Being known as a social conservative is not something that is going to sell to Republicans in New Hampshire,” said Andy Smith, a pollster at the University of New Hampshire who said Mr. Santorum’s support has languished in the single digits in his surveys.

“On the issue of abortion, likely Republican primary voters are more pro-choice than the country as a whole,” and “41 percent of GOP voters also are opposed to repealing the state’s gay-marriage law,” Mr. Smith said.

Mr. Santorum will be in New Hampshire next week for a debate at St. Anselm College in Manchester, where he will join former Govs. Mitt Romney of Massachusetts and Tim Pawlenty of Minnesota, former House Speaker Newt Gingrich, U.S. Reps. Ron Paul of Texas and Michele Bachmann of Minnesota, and former corporate CEO Herman Cain. Former New Mexico Gov. Gary E. Johnson is also running for president, but was not invited to the debate.